The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 22, 1981
Filed:
Jan. 11, 1980
Applicant:
Inventor:
Peter E Walters, Southall, GB;
Assignee:
EMI Limited, Hayes, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
324307 ; 324309 ;
Abstract
In a nuclear magnetic resonance imaging apparatus it has been proposed to excite resonance preferentially in a cross-sectional slice of a patient's body by applying a field gradient pulse in conjunction with a pulse of RF. It has been found that the shape of the RF pulse envelope can be chosen to reduce excitation outside the chosen slice. It is proposed that the RF envelope should be a unidirectional pulse of which both the rising and falling parts are monotonic curves lying between limits given by sin.sup.3 t and sin.sup.10 t curves, preferably sin.sup.5 t. An acceptable curve may fall below sin.sup.10 t in the skirts but should not change sign.